[Elecraft] [K3] Roofing filters are misunderstood

[Greg]

No problem Jerry.  Didn't seem to make much sense hashing out something
that was already clarified by the designers. :)

73
Greg



On Mon, May 12, 2014 at 9:59 AM, Jerome Sodus <jsodus at comcast.net> wrote:

>   Thank-you, Greg.
>
> Excellent.
>
> Jerry KM3K
>
>
>  ------------------------------
>
> *From:* Greg [mailto:ab7r at cablespeed.com]
> *Sent:* Monday, May 12, 2014 12:52 PM
> *To:* Jack Brindle
> *Cc:* Jerome Sodus; elecraft at mailman.qth.net
>
> *Subject:* Re: [Elecraft] [K3] Roofing filters are misunderstood
>
>
>
> http://www.elecraft.com/K3/Roofing_Filters.htm
>
>
>
>
>
>
>
> On Mon, May 12, 2014 at 9:45 AM, Jack Brindle <jackbrindle at me.com> wrote:
>
> Jerry,
>
> Why do you say it has been corrupted? This is exactly the purpose for the
> Roofing Filters in the K3.
>
> Jack B, W6FB
>
>
> On May 12, 2014, at 9:33 AM, Jerome Sodus <jsodus at comcast.net> wrote:
>
> > Hello Bill,
> > The term "roofing-filter" made sense back in the 1980's when I designed
> > roofing-filters at 70 MHz.
> > Bandwidths would be in tens of KHz.
> > The purpose then was to protect downstream circuitry by rejecting very
> > strong out-of-band signals that could cause overload; selectivity was not
> > the purpose.
> > Selectivity was done further downstream.
> > So the term has become corrupted over the years.
> > 73 Jerry KM3K
>
>
>